The present invention is related to electronic systems for the detection and location of hazardous agents and, more particularly, to such systems based upon mobile telephone networks.
Sources of hazardous agents, such as biological, chemical, and radioactive materials, are plentiful in modem society and the possibilities of their release must be faced. Furthermore, given the present threat of terrorism, the dangers of the purposeful release of these agents is also a real possibility. Hence there is the need for a network of ubiquitous detectors which are capable of sensing such biological, chemical, and radioactive agents.
Various networks, detectors and combinations of networks and detectors have been proposed in response. One proposal has been the deployment of such detectors in simple combination with, or as an integral part of, cellular (or cell) telephones. Cell telephones are ubiquitous in modem societies and are transported everywhere. As normally used telephones, the telephone owners are likely to keep the telephones charged and in good working order. Canadian Patent No. 2,418,612, which issued to Marian Gavrila and Gabriel Patulea, describes the incorporation of chemical, radiation, and biological agent detectors in cell phones and U.S. Pat. No. 6,697,645, which issued to J. M. MacFarlane, discloses the incorporation of environmental sensors into cellular phones.
Efforts at numerous national laboratories, universities, and businesses have focused mostly on sensor development. For example, Lawrence Livermore National Laboratory is currently developing radiation detectors which can be embedded in PDA (Personal Digital Assistant)/cell telephone devices which are part of a wireless network known as RadNet. These devices are to be deployed with specially trained personnel, such as firefighters, utility workers, police, and custom agents, as a first response team. But the relatively low number of such people compared to the general population means that the detectors, or sensors, must necessarily be highly sensitive and accurate. These requirements imply that deployment of such a network system is likely to be many years away. Other efforts include research on wireless networks of autonomous sensor devices; e.g., Graviton Corp. of San Diego is developing a network independent of existing cell telephone infrastructures.
Despite these efforts, these network systems suffer from various deficiencies, such as lack of geographical coverage, and high costs of installation and maintenance. The distribution of detectors/cell telephones to special personnel limits the distribution of the sensor network. Sensitive and accurate detectors raise the initial and maintenance costs of the sensor/PDA/cell telephone (or autonomous sensor) devices and the installation of special wireless networks further adds the total of network system costs.
On the other hand, the present invention provides for a network system which is inexpensive to operate with easy installation and low maintenance costs.